The friends were separated as people ran for their lives from a white van ploughing into pedestrians on London Bridge.

Sara Zelenak Facebook - Sara Zelenak

Ms Zelenak's mother Julie Wallace was told earlier this week how her daughter had narrowly missed being caught up in the two previous terror attacks in the UK in the past three months - a similar attack at Westminster where four pedestrians and a policeman were killed and the suicide bombing at a Manchester pop concert which killed 22 people.

"Where (the) policemen were stabbed three months ago, she was there the day before in the exact same spot," Ms Wallace told 97.3FM radio in Brisbane.

"The one with Ariana Grande (in Manchester), she was going to go to the concert."

The crowd at the Manchester Arena was made up of children who went with their parents to see the Ariana Grande concert.

Ms Wallace said she had spoken to her daughter on Friday afternoon, who had been excited about an upcoming trip where she would join her in Paris.

"She said, 'Oh mum! It's only 28 days until you and I and dad can have baguettes and cheese and croissants in Paris. I'm so excited to go to Paris!' because she hasn't been.''

"She's a very smart, sensible girl, she is healthy, fit, trim, taut, terrific - she doesn't do anything wrong in any way.

"She's very sensible, far more sensible than I was at her age."

Ms Wallace told 97.3FM she felt "absolute terror'' when she heard about the attack.

Police and bystanders treat a wounded person near London Bridge.Supplied

She said Ms Zelenak had been travelling since March, having a "wonderful trip'' and life experiences, and she was counting down the days until she travelled to Europe to meet her daughter to continue the holiday.

"But horror, absolute horror,'' she said.

Kirsty Boden of South Australia was also killed in the London Bridge attacks.Facebook

South Australian nurse Kirsty Boden was confirmed dead by UK authorities overnight.

Two other Australians are recovering after being stabbed in the neck by the terrorists.

Candice Hedge, 31, of Queensland, is recovering in hospital after being attacked in Elliott's cafe. Andrew Morrison, of Darwin, is home in Australia after being stabbed in the throat as he walked down the street.